Receptive fields of retinal neurons: New themes and variations.

Receptive fields have long been central to understanding signal processing in the visual system. Initially defined as the region of visual space that influences a given neuron's activity, receptive fields are now recognized to encompass additional dimensions such as time and color. This multidimensional representation provides a window into how visual neurons filter incoming stimuli. In the retina, receptive fields emerge from neuronal processing by a multi-layered circuit. Recent research on temporal, chromatic, and adaptive processing in the retina has revealed more complex receptive fields than were initially recognized. This review emphasizes new research on receptive fields in the retina and highlights approaches that promise to expand our understanding of retinal receptive fields.